The Environmental Protection Agency says that a recent spike in the level of PCBs on the Hudson River was an isolated incident caused by river conditions.
The EPA announced on Monday, Aug. 3, that a monitor at Thompson Island Dam indicated PCB levels had exceeded 500 parts per trillion, which is what the EPA considers to be the safety threshold. The peak occurred sometime between Saturday and Sunday. Subsequent samples taken on Sunday and Monday mornings showed 337 and 434 ppt, leading the agency to conclude that a fast moving river caused the spike.
The spike was the first time PCB levels have exceeded the threshold since dredging operations began in May.
Coincidentally, dredging operations were suspended Monday because the current was too strong, a condition brought on by heavy rainfall. Dredging has since resumed.
Tests taken at Schuylerville, the next testing site downstream, on Sunday and Monday registered a high of 196 ppt. Thompson Island Dam is just below Fort Edward, where the dredging operation is ongoing.
It was a spike of PCBs in the water that went by the station at that particular time, said EPA Spokeswoman Kristen Skopeck. "But when we took subsequent samples they were well below it."
The EPA has an agreement to pay for alternative drinking water sources for towns along the Hudson when the PCB levels exceed the threshold, and Skopeck said the agency will likely pay for a 24-hour supply in light of the spike. The towns of Waterford and Halfmoon have been drawing water from the City of Troy since the dredging began at their own expense.
Halfmoon Supervisor Mindy Wormuth said the gap between the spike and notification proves the town was right to avoid river water altogether during the dredging.
"It definitely affirms the decision we made," said Wormuth. "This exceedance happened sometime on Saturday, and we're finding out about it on Monday morning."